For years, it was assumed this could have been a Constitution-class vessel based on a ship list provided in the The Making of Star Trek, but the timeframe of its loss predates that ship type by many years. The registry listed here was supplied not from the episode, but was devised by Michael Okuda for his reference works. In one of those works, the first edition of the Star Trek Encyclopedia, Okuda suggested the ship could be Daedalus-class, a suggestion that wasn't repeated in future editions of the Encyclopedia. The Last Unicorn roleplaying reference originated this vessel's Ranger-class designation.